Duplex document retard separation and feeding with reduced image smudging

In a document separation and feeding method in which flimsy image bearing document sheets are separated and sequentially singularly fed downstream from an upstream stack thereof by a retard type sheet separator-feeder, said separator-feeder including a frictional elastomeric surface sheet feeding member operatively engaging a frictional elastomeric surface sheet movement resisting retard member to form a closed document sheet retarding nip for retarding the document sheets in said stack other than a single document sheet being fed by said sheet feeding member, wherein said retard member and said sheet feeding member engage one another with a normal force in said closed document sheet retarding nip, and an intermittent drive system for intermittently driving said sheet feeding member;

• the improvement in separating and feeding document sheets with previously printed images with said separator-feeder comprising:
• (a) feeding said document sheets from said stack into said document sheet retarding nip,
• (b) operating said intermittent drive system to drive said sheet feeding member in said downstream sheet feeding direction for only a short downstream document sheet feeding distance which is only a minor portion of the dimension of said document sheets, so that said single document sheet being fed by said sheet feeding member extends only partially downstream from said closed document sheet retarding nip, then
• (c) reversing said intermittent drive system to positively reverse drive said sheet feeding member in said upstream sheet feeding direction, while said sheet feeding member remains engaged with said retard member in said closed document sheet retarding nip for only a short reverse document sheet feeding distance which is only a minor portion of the dimension of said document sheets sufficient to eject document sheets from said retard nip other than said single document sheet being fed by said sheet feeding member, which short reverse document sheet feeding distance is less than said short downstream document sheet feeding distance so as to retain said single document sheet being fed by said sheet feeding member in said closed document sheet retarding nip, then
• (d) operating said intermittent drive system to positively drive said sheet feeding member in said downstream sheet feeding direction through said closed document sheet retarding nip, for at least a substantial portion of the dimension of said single document sheet,
• (e) so that said single document sheet being fed by said sheet feeding member may be positively fed downstream out of said closed document sheet retarding nip yet without document image smearing against other document sheets in said closed document sheet retarding nip.